linux/drivers/acpi/platform_profile.c

182 lines
4.1 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-or-later
/* Platform profile sysfs interface */
#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/platform_profile.h>
#include <linux/sysfs.h>
static struct platform_profile_handler *cur_profile;
static DEFINE_MUTEX(profile_lock);
static const char * const profile_names[] = {
[PLATFORM_PROFILE_LOW_POWER] = "low-power",
[PLATFORM_PROFILE_COOL] = "cool",
[PLATFORM_PROFILE_QUIET] = "quiet",
[PLATFORM_PROFILE_BALANCED] = "balanced",
[PLATFORM_PROFILE_BALANCED_PERFORMANCE] = "balanced-performance",
[PLATFORM_PROFILE_PERFORMANCE] = "performance",
};
static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
static ssize_t platform_profile_choices_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int len = 0;
int err, i;
err = mutex_lock_interruptible(&profile_lock);
if (err)
return err;
if (!cur_profile) {
mutex_unlock(&profile_lock);
return -ENODEV;
}
for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
if (len == 0)
len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
else
len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
}
len += sysfs_emit_at(buf, len, "\n");
mutex_unlock(&profile_lock);
return len;
}
static ssize_t platform_profile_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
int err;
err = mutex_lock_interruptible(&profile_lock);
if (err)
return err;
if (!cur_profile) {
mutex_unlock(&profile_lock);
return -ENODEV;
}
err = cur_profile->profile_get(cur_profile, &profile);
mutex_unlock(&profile_lock);
if (err)
return err;
/* Check that profile is valid index */
if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
return -EIO;
return sysfs_emit(buf, "%s\n", profile_names[profile]);
}
static ssize_t platform_profile_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int err, i;
err = mutex_lock_interruptible(&profile_lock);
if (err)
return err;
if (!cur_profile) {
mutex_unlock(&profile_lock);
return -ENODEV;
}
/* Scan for a matching profile */
i = sysfs_match_string(profile_names, buf);
if (i < 0) {
mutex_unlock(&profile_lock);
return -EINVAL;
}
/* Check that platform supports this profile choice */
if (!test_bit(i, cur_profile->choices)) {
mutex_unlock(&profile_lock);
return -EOPNOTSUPP;
}
err = cur_profile->profile_set(cur_profile, i);
if (!err)
sysfs_notify(acpi_kobj, NULL, "platform_profile");
mutex_unlock(&profile_lock);
if (err)
return err;
return count;
}
static DEVICE_ATTR_RO(platform_profile_choices);
static DEVICE_ATTR_RW(platform_profile);
static struct attribute *platform_profile_attrs[] = {
&dev_attr_platform_profile_choices.attr,
&dev_attr_platform_profile.attr,
NULL
};
static const struct attribute_group platform_profile_group = {
.attrs = platform_profile_attrs
};
void platform_profile_notify(void)
{
if (!cur_profile)
return;
sysfs_notify(acpi_kobj, NULL, "platform_profile");
}
EXPORT_SYMBOL_GPL(platform_profile_notify);
int platform_profile_register(struct platform_profile_handler *pprof)
{
int err;
mutex_lock(&profile_lock);
/* We can only have one active profile */
if (cur_profile) {
mutex_unlock(&profile_lock);
return -EEXIST;
}
/* Sanity check the profile handler field are set */
if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
!pprof->profile_set || !pprof->profile_get) {
mutex_unlock(&profile_lock);
return -EINVAL;
}
err = sysfs_create_group(acpi_kobj, &platform_profile_group);
if (err) {
mutex_unlock(&profile_lock);
return err;
}
cur_profile = pprof;
mutex_unlock(&profile_lock);
return 0;
}
EXPORT_SYMBOL_GPL(platform_profile_register);
int platform_profile_remove(void)
{
sysfs_remove_group(acpi_kobj, &platform_profile_group);
mutex_lock(&profile_lock);
cur_profile = NULL;
mutex_unlock(&profile_lock);
return 0;
}
EXPORT_SYMBOL_GPL(platform_profile_remove);
MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
MODULE_LICENSE("GPL");